The invention is based on the object of developing a blocking mechanism for switching devices which makes it possible to arrest switching devices of different widths with regard to their manual control element with a blocking mechanism in a simple way. The solution achieving the object described is provided by a blocking mechanism.
There are a wide variety of blocking mechanisms on the market. For instance, it is known to clamp a switch knob, as a manual control element, with a type of clamp which bears flat against the switching device, it being possible for the clamping screw to be blocked against loosening by a latching mechanism (U.S. Pat. No. 5,079,390). In comparison with box-like formations which block access to the manual control element, the known configuration makes it possible to secure switching devices against inadmissible operation independently of their width. However, the known blocking mechanism must be produced from strong material, such as metal, since relatively great forces have to be absorbed internally. EP 0 172 771 A1 discloses, furthermore, a device for locking a miniature circuit-breaker according to the precharacterizing clause of claim 1.
Metallic materials in the area of the manual control element do not meet the relevant safety requirements in the case of all configurations of protective switching devices.
The invention is based on the object of developing a blocking mechanism for switching devices which makes it possible by a different means to arrest switching devices of different widths with regard to their manual control element with a blocking mechanism in a simple way.
The solution achieving the object described is provided by a blocking mechanism as claimed in claim 1.
The retaining lugs may in this case engage in sealing holes of the switching device or protective switching device which are usually present in any case. A blocking mechanism of this type can be produced from insulating plastic, and it can be designed and used for a plurality of devices with manual control elements of different widths.
One retaining element may form a carriage guide in which a carriage formed with respect to the other retaining element is guided under spring action. The retaining elements may also be guided in each other in the manner of a collet guide and have a torsion spring for the spring action.
The retaining elements may also be movably guided in relation to each other by a telescopic guide under spring action.
In the case of all these solutions, the spring providing the spring action may form the retaining lugs with its ends. In the case of the configurations mentioned, the catch element may engage with a tooth in a respective recess for each position in the guide of the retaining elements, whereby the retaining elements are locked in the desired position.
The catch element may be respectively attached in an articulated manner on one of the retaining elements by a film gate hinge.
According to another alternative, the retaining elements may be held in the respective retaining position by exchangeable shackle springs, the catch element being designed such that it can swivel into the shackle. The spring ends may be made to match the width of the switching device respectively to be blocked by the spring ends being of different lengths.
Finally, the guide of the retaining elements may be designed as a post which engages in a cylindrical hole of a retaining element.
The post may be surrounded by a cylindrical spring for the spring action.
According to a further configuration, the retaining elements may be held in the retaining position by exchangeable horizontal shackle springs of different widths, the catch element being provided with grooves which in the locking position receive the legs of the springs of different widths and consequently lock the retaining elements.